Fountain pen



O.'M|TCHELL.

FOUNTAIN PEN.

APPLICATION men JAN. 14, I922.

Patentd. Oct. 10, 19229 i t Figure 1;

the. rod 6.1

Patented that. id, H92

onrvnn MrrotrnL-n, or isnookmnn, :itiissacriusnrcrsi ronnrrarn PEN.

Application filed January 14, 1922. Serial No. 529,204.

To all whom it ma yiconcerm i Be it known that l, OLIVER MITCHELL, a

citizen ofjt he United States, residing at Brook-line, in the county ofNorfolk and State of Massachusetts, have invented certain new and usefulffmprovemel'its in Founr tam Pens, of which the following is aSPGClflCillJlOll. i i

In the drawingsi v Figure 1 1s a longitudinal sectional elefountain penembodylng my invation of. a

vent1on;.. p t

Figure 2 is a crosssection on l1ne, 2 2 of Figure 3 is a cross-sectionon line 3--8 ofFigure 1; Y

Figure 4 1s a perspective new of the dlsk i l l n i Figure 5 1s alongltudlnal View partly in section of the upper or rear part of thedevice of Figure 1, the interior mechan sm being-as at the upper orrearward stroke of As shown in the drawings, A is a fountain carrying atone end an ink feed bar B,

supporting in proper positiona pen C and at the otherend a gland Dhaving a central perforation d. Within the, fountain is con tained achamber E closed at the rear end as a support against cross-strains whenthe rod 6 is extended outside the gland and also provides a finish. Thefeed-bar B is provided with a central opening, 5, coincident with thelongitudinal axis of the fountain, and secured in line with thisaperture and connecting therewith. is a pipe F extending axially of thefountain to andwithin the chamber E. The end of pipe F, within thechamber, is closed by a collar which serves 1 not only to plug the endof the pipe F but also as a stop and below collar 7, and aperture f isformed in the side of pipe F connecting with the interior of the pipe. A

short distance below collar 7 and aperture f a second stop F ispositioned and mounted on pipe F between the two stops is a disk Gfitting pipe F and frictionally engaging at its outer edges or sides,the inner walls of disk from its forward position abutting the chamberIt will beobserved that, at theopen end of the chamber fl and extendingupward, the wall of the chamber is slotted,

as ate for a purpose hereinafter explained. .60

it will now be obvious that upon actuari tion of the chamber E in eitherdirection, by means of the rod, 6, the disk G by virtue of itsfrictionali engagement with the inner side of the walls of chamber Ewill move withthe chamberwwithin the limits of m0- tionprescribed by thestops 7", 7 upon the a 1 pipe F. l/Vhen the chamber E moves up orrearwardly, its first movement carries the stop f to its rearwardposition, abutting stop f, in so moving COVQIIIIg aperture If. 1n pipeF. Contmuedrearward movement 1 of chamber E will, as the chamber reachesthe limit of its movement inthis direction, brlng the upper or innerends of slots 6 above the upper or inner surface of diskG opening.communication between the inside of chamber E and the inside of fountainA."

The movement of the chamber, as described, has rarefied the air withinthe chamber and as soon as communication is opened, air enters from thefountain to fill the partial vacuum. Upon'a reversal of movement, theinitial movement of the chamber carries the disk Gr with it and opensthe aperture 7.

The diskstopping against stop 7. the cham ber continues carrying theslots 6 below the upper orinner surface of disk G, closing communicationbetween-the inside of the chamber and the inside of the fountain andtrapping the air in the chamber, which is then by further movement ofthe chamber, forced through aperture f, pipe F, and

aperture 5 in feed-bar B, out of the fountain pen, the extruded. airbeing replaced in the fountain by ink forcedthrough the ink feed channel6 in the feed-bar, by atmospheric pressure, the lower or pen end of thefountain being submerged in an ink supply, as

will be understood.

It will be observed that in my improved fountain pen the chamber E iscombined by meansof an actuating rod 6 with a gland D closing the rearend of the fountain. This is a practical feature of importance as bymeans of such a gland as I have shown, it is possible to close the rearend of the fountain fluid tight and to maintain this condition,

which is an essential of successful operation in order to obtain thedesired filling action by means of an air pump of the cylinder andpiston type, completely enclosed within. the fountain but distinct inall its parts from the fountain. Air from the fountain is drawn into theair pump and extruded from the pump and fountain through a suitable airduct connected to the air pump, ink simultaneously entering through theink feed fissures to replace the extruded air. This is a feature of myimprovement. As a practical matter the utilization of the fountain asthe cylinder or chamber element of a piston pump is undesirable as it isifncult and expensive to form the inner walls of the fountain to a truecontour or to give them a sufficiently smooth surfaceto preventleakageand undue friction and wear of the piston element. The provision of anair pump entirely independent of the fountain and en- .tirelyenclosed'therein is therefore of practioal importance. A secondaryfeature of my invention is the fact that preferably the chamber E,constituting a part of the air pump, is not fitted to the interior ofthe fountain, but is loose therein, with air space at the sides thereof,the chamber being guided in its longitudinal movements by the disk G andpipe F. The chamber E it will be observed forms the cylinder element ofan airpump, while the disk G and pipe F formthe piston element of theair pump.

At the lower edge of the chamber E, I have shown aninwardly projectingelement, It, whi'ohis in fact an annulus, screwed into place. Thefunction of this annulus is that in the possible case of the disk Gbecoming fast to the pipe F, due to the drying of ink between the parts,the annulus, h, as the chamber E is drawn rearwardly' or up, willcontact with: the disk G and forcibly disengage it, so that it maythereafter function as designed, by frictional actuation. At the upperend of the chamber E, within, a cavity, ho, is formed to receive thecollar 7".

This cavity is slightly deeper than the thickness of the collar f, asthat, in case the disk G is gumined and sticks at its upper or rearwardposition, the outer edge of the cavity it will contact with the disk (3on the down stroke and forcibly disengage it, so that it may thereafterfunction as designed by frictional actuation.

I claim:

1. In a fountain pen, a fountain, carrying a feed bar and pen at itsfront end; a gland, closing the rear end of the fountain; a BMW-- ablecylinder, loosely fitting within the fountain and open at its front endrod, fast to the closed end of the cylinder and passing through thegland; a pipe, within the fountain and arranged longitudinally thereof,

opening without the fountain at the front end and into the cylinder atthe rear end; a disk, mounted upon the rear end of the pipe between apair of stops and frictionully engaging the inner walls of the cylinder;a passage from the inside of the cylinder, above the disk, to the insideof the fountain, opened and closed by the reciprocation of the cylinder.

2. In a fountain pen, an air pump, made up of a movable cylinder, closedat its rear end and open at the other end and having an inwardprojection at its open end; a pipe Within the fountain andarinngedlongitudinally thereof, opening without the fountain at its front endand into the cylinder at the rear end; a disk mounted uponthe rear endof the pipe between a pair of stops and frictionally engaging the innerwalls of the cylinder, the outer edge of the disk projecting into thepathof the projection, substantially as and for the purpose described.

Signed at Boston, Massachusetts, this tenth day of January, 1922.

OLIVER MITCHELL.

